Objectives: The aim of this study was to examine the clinicopathological features of extensive spreading type of squamous cell carcinoma (SCC) of the esophagus with invasion restricted to the submucosa.
Methods: Thirty-eight submucosal SCC were studied histopathologically, and five of these 38 submucosal SCC, which demonstrated an extensive spreading-type SCC in which the size of the SCC was over 5 cm in longitudinal length while extending entirely across the esophageal lumen in a circumferential spread, are described in detail.
Results: The extent of SCC depended mainly on the extent of intraepithelial carcinoma (IEC) and ranged from 50 to 135 mm in longitudinal length. IEC existed continuously in four cases, and multiple IEC existed separately in one case. An epithelium showing dysplasia was present in all cases, and the involvement of the glands and ducts by IEC was present in two cases. There was only one invasive part of SCC observed in one case, and three to 10 invasive parts of SCC were observed in the other four cases; various features of invasion, including an invasive SCC from the esophageal glands and ducts, were also present.
Conclusions: The extensive spreading-type SCC of the esophagus, which was considered to result from the widespread or multiple carcinomatous changes of the esophageal epithelium, was found to not be as rare as generally thought. The multiple and various features of the invasive parts of SCC suggested the simultaneous development of a downward invasion of SCC at different areas in extensive IEC.